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Biomedical subjects

A Alho

Publications and source records attributed to A Alho.

At least 127 records · Page 7Linked to original sources
PubMed1982

Filling of a bone defect during experimental osteotaxis distraction.

Gradual distraction of a tibiofibular bone osteotomy in 14 rabbits was compared with a neutral osteotomy in 14 control rabbits using an osteotaxis device as fixation. The osteotomy was distracted for a period of 8 weeks at a rate of 1 mm/week. The control osteotomies united in 5 to 6 weeks with minimal external callus formation. In the distraction group, the periosteum and endosteum participated in the filling of the distraction gap. The most vigorous osteoblastic activity was observed in the middle of the osteotomy gap (growth zone) where calcification was delayed. In the distraction group the bone united in 6 to 7 weeks, not significantly later than in the controls. Two instances of non-union (2/14) were observed in the distraction group.

Animals↗
PubMed1982

Migration of the femoral stem in hip arthroplasties. Analysis of associations with structural, radiological and follow-up variables.

Medical and/or distal migration of the prosthetic stem was found in 63 out of 337 patients (19 per cent) treated surgically with a Christiansen hemiprosthesis, a Christiansen total hip prosthesis or a Charnley total hip prosthesis. Fractured bone cement, radiolucent zones at the cement/bone interface, resorption of the femoral calcar and cortical sclerosis were all associated with migration. Varus position of the Christiansen total hip prosthesis was significantly associated with medical migration, and a short stem was significantly associated with distal migration. The other structural variables could not be linked with migration. Distal migration was pain-inducing and was significantly associated with late infection. Medical migration had a less distinct association with pain, and was not correlated with infection. Both medical and distal migration were time-dependent, and 4 or more years after operation about 2.5 per cent of the prosthetic stems had migrated.

Bone Cements↗
PubMed1982

Histological changes in clinical half-joint allograft replacements.

Fourteen biopsies of cartilage and subchondral bone were taken from nine half-joint knee allografts 10 weeks to 8 years after the transplantation. Deep-frozen cadaver grafts were used to replace the defective half-joint after resection for bone tumour. The biopsies revealed a slow substitution of the dead grafted bone and cartilage. Subchondrally, signs of incorporation could be seen from 12 months on. The dead cartilage matrix degraded gradually and slow simultaneous regeneration was observed. Thus, fibrocartilage was seen on the articular surface of the graft at 12 months, chondrocytes were present at 18 months, but islands of hyaline cartilage were not seen earlier than 7 years after the transplantation. In accordance with the earlier clinical findings, the histological signs of rejection were minimal. The long-term result of half-joint allograft transplantation is obviously dependent on the cartilage component.

Adolescent↗
PubMed1982

Effect of instability of experimental fracture healing.

Bilateral tibial osteotomy with fracturing of the fibula was performed on ten Wistar rats weighing 300--350 g. Intramedullary nailing was performed with 1.4 mm nails after reaming. On the left side solid stainless rods were used, while on the right side the nails had a middle part made of titanium-nickel wire covered with polyvinylchloride (PVC), giving the nail a high degree of flexibility. After 8 weeks, nine of the ten flexible nails showed fracture of the central wire. The continuity was, however, maintained by the PVC tube. The bones with flexible nailing always showed hypertrophic callus while there was only scanty callus on the side with rigid nailing. Strength, deformation at fracture and stiffness were measured in a three-point bending test after removal of the solid nails and the fibulae. The strength of the tibiae was greatest on the side with flexible nailing, as was the deformation at fracture. The mean stiffness was higher in the bones with rigid nails, but the difference here was not statistically discernible.

Animals↗
PubMed1982

The risk of acetabular protrusion following prosthetic replacement of the femoral head.

A total of 24 patients treated with hemiarthroplasty showed a crude frequency of acetabular protrusion of 26 per cent. Two factors were associated with the development of protrusion: the length of the follow-up period and previous hip operation. The frequency of protrusion was estimated using logistic regression techniques based on information concerning the age of the patients, the length of the follow-up period and any previous hip operation. The frequency ranged from 4.8 per cent for a patient of 75 years or under, with a follow-up period of less than 12 months and no previous hip operation, to 61 per cent for patients of over 75 years, with a follow-up period exceeding 12 months, and a previous hip operation. Patients of over 75 years were 1.7 times more likely to develop protrusion than younger patients, patients previously operated on were 2.3 times more likely to develop protrusion than those not operated on previously, and patients with a follow-up time period exceeding 12 months were 7.9 times more likely to develop protrusion than patients with a shorter follow-up time.

Acetabulum↗
PubMed1982

Fat embolism syndrome--a variant of post-traumatic pulmonary insufficiency.

The fat embolism syndrome is defined as a variant of post-traumatic pulmonary insufficiency complicating musculoskeletal trauma. It occurs up to 28% of cases depending to a certain extent on the magnitude of the trauma. Tissue fat embolization into pulmonary and other capillaries and microthrombus formation appear to be the factors causing the microvascular disorder in the lungs, brain, kidneys, skin etc. Pulmonary malfunction and respiratory distress is the most important part of the fat embolism syndrome. The cornerstone of treatment is in supporting respiratory care. Early and effective stabilization of fractures and pharmacological glucocorticoid therapy appear to be beneficial. The syndrome is usually self-resolving after several days. The central clinical problem is early detection of the syndrome.

Adult↗
PubMed1981

Pathophysiology of massive trauma with therapeutic implications.

In addition to its local effects, severe trauma has several consequences for the whole organism. Partly, these are hormonal, humoral and neural regulatory mechanisms - negative feedback mechanisms to regain homeostasis, a balance of the "milieu intérieur". Blood loss and disturbances in the fluid compartments is one of the central pathological features. The shock period is accompanied by mobilization of defense mechanisms and energy. The length and extent of of the catabolic phase depends on the extent of the injury, the effectiveness of the therapeutic efforts and the disturbances of organ and system functions. Repair proceeds gradually aiming at anatomical and functional restitution.

Acute Kidney Injury↗
PubMed1981

Importance of thermoregulation in traumatic and haemorrhagic shock in the anaesthetized rabbit.

The effects of external thermal support was studied in 66 anaesthesized adult rabbits divided into six groups: control, traumatic shock and haemorrhagic shock; each of these groups had a subgroup with an external thermal support and a subgroup without support. During the four hour experimental period, anaesthesia alone resulted in a reduced core temperature and metabolic acidosis. The external thermal support attenuated these changes. In the shocked animals, the external thermal support reduced the mortality, assisted the body's thermoregulation and reduced the adverse metabolic effects of shock.

Acid-Base Equilibrium↗
PubMed1981

The effect of hyperbaric oxygenation on experimental Bacteroides fragilis infection in the rat liver.

An experimental intra-abdominal model for producing Bacteroides fragilis abscesses in the rat liver was used to evaluate the therapeutic effect of hyperbaric oxygenation (HO) at 3 ATA (atmospheres absolute). Two different experiments were performed. In the first experiment one half of the animals were inoculated with B. fragilis, and the other half were sham-operated. Whether the inoculated or sham-operated animals were given single or repeated HO treatment at 3 ATA for 90 min, the bacteriological pattern was about the same. In the second experiment all the animals were inoculated with B. fragilis; half of the animals were given HO at 3 ATA for 90 min as single or repeated treatments, and the other half acted as controls receiving no HO. Even if the HO treatment was given every day during 21 days, B. fragilis could be recovered in all inoculated animals 22 days after inoculation.

Animals↗